The effect of extreme environmental temperature spikes on mosquito longevity, fertility and ability to transmit viruses

As a direct consequence of climate change, the habitable range for mosquitoes is shifting rapidly. Mosquitoes are disappearing from some tropical regions where temperatures are increasing and rainfall reducing. At the same time, mosquitoes are spreading polewards with the rising temperatures, bringing with them important animal and human viruses. The different environmental conditions they face will determine the extent of the new geographic ranges, for both mosquitoes and their viruses.

Longevity, fertility and vector competence are central temperature-dependent traits which determine the geographic range of mosquitoes and the epidemiology of the viruses. Typically, these traits are studied either in highly controlled laboratory conditions, or observed more loosely in field settings without experimentation.

Such previous studies have shown, in the fruit fly Drosophila, that males are often sterilised by temperatures several degrees lower than their lethal limit, resulting in restriction of their geographic range. Conversely, in Culicoides biting midges, short heatwaves can actually increase their ability to transmit viruses.

If these effects are also present in mosquitoes, they would have contrasting and interacting effects on the ranges of both mosquito and virus, and consequently, who and where is at risk.

What you will do:

During your PhD project, you will combine field collection and laboratory experimentation to understand the effect of natural heatwaves on two native UK species: Culex pipiens, and Ochlerotatus detritus. Both of which are capable of transmitting mosquito-borne viruses.

1. In the lab, you will administer UK-heatwave representative thermal-shocks to colony Culex mosquitoes and assess the effects on mortality and fertility, to enable estimation of thermal tolerance.
2. Using these results, sub-lethal temperatures (which represent a survivable heatwave) will be administered to colony mosquitoes. Mosquitoes will then be challenged with the emerging Usutu virus, to investigate environmentally induced vector competence.
3. Wild Culex pipiens, and Ochlerotatus detritus larvae/pupae will be collected from field sites after natural heatwaves. Resultant adults will be assessed for fertility, mortality and challenged with Usutu virus, to confirm your lab experiment results with 'real-world' data and mosquitoes.
4. During experimental downtime, you will be trained in climate modelling and use your experimental results to model the thermal range, geographic limitations, and virus transmission of these two species in the UK, both now and under future climate scenarios. 

HOW TO APPLY

Notes and details of how to apply are available here: https://accedtp.ac.uk/acce-dtp-phd-opportunities-at-university-of-liverpool/

All applicants to ACCE must complete the ACCE personal statement proforma. This is instead of a normal personal/supporting statement/cover letter. The proforma is designed to standardise this part of the application to minimise the difference between those who are given support and those who are not.

The ACCE DTP is committed to recruiting extraordinary future scientists regardless of age, ethnicity, gender, gender identity, disability, sexual orientation or career pathway to date. We understand that commitment and excellence can be shown in many ways and have built our recruitment process to reflect this. We welcome applicants from all backgrounds, particularly those underrepresented in science, who have curiosity, creativity and a drive to learn new skills.

Informal enquiries may be made to marcus.blagrove@liverpool.ac.uk